The present disclosure relates to an optical scanning device that includes a plurality of light sources for emitting light beams and a deflector for reflecting the light beams toward corresponding scanned surfaces, and to an image forming apparatus that uses the optical scanning device.
An optical scanning device for use in a color laser printer includes, for example: a plurality of light sources for emitting laser beams respectively for colors of cyan, magenta, yellow and black; a deflector (polygon mirror) for deflecting the laser beams such that the laser beams scan the circumferential surfaces (scanned surfaces) of the photoconductor drums for respective colors; and focus lenses for focusing the deflected laser beams on the circumferential surfaces. The deflector may be used in common by a plurality of laser beams.
There has been disclosed a technology in which two optical scanning devices are used to scan four photoconductor drums disposed adjacent to each other. Each of the optical scanning devices includes two light sources and a deflector. In this case, a laser beam emitted from a light source is deflected at a first position on the circumference of the deflector, a laser beam emitted from the other light source is deflected at a second position that is on the opposite side to the first position.